MEG3 (Maternally Expressed Gene 3) is a non-coding RNA that is highly expressed in the normal human brain and pituitary. Expression of MEG3 is lost in gonadotroph-derived clinically non-functioning pituitary adenomas. Meg3 knock-out mice were generated to identify targets and potential functions of this gene in embryonic development and tumorigenesis. Gene expression profiles were compared in the brains of Meg3-null embryos and wild-type litter-mate controls using microarray analysis. Microarray data were analyzed with GeneSifter which uses Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and Gene Ontology (GO) classifications to identify signaling cascades and functional categories of interest within the data set. Differences were found in signaling pathways and ontologies related to angiogenesis between wild-type and knock-out embryos. Quantitative RT-PCR and histological staining showed increased expression of some VEGF pathway genes and increased cortical microvessel density in the knock-out embryos. These results are consistent with reported increases in VEGF signaling observed in human clinically non-functioning pituitary adenomas. In conclusion, Meg3 may play an important role in control of vascularization in the brain and may function as a tumor suppressor by preventing angiogenesis.
Increased expression of angiogenic genes in the brains of mouse meg3-null embryos.
Specimen part
View SamplesHuman disease caused by highly pathogenic avian influenza (HPAI) H5N1 can lead to a rapidly progressive viral pneumonia leading to acute respiratory distress syndrome. There is increasing evidence suggests a role for virus-induced cytokine dysregulation in contributing to the pathogenesis of human H5N1 disease. The key target cells for the virus in the lung are the alveolar epithelium and alveolar macrophages, and previous data has shown that compared to seasonal human influenza viruses, equivalent infecting doses of H5N1 viruses markedly up-regulate pro-inflammatory cytokines in both primary cell types in vitro. The dysregulation of H5N1-induced host responses is therefore important for understanding the viral pathogenesis.
Systems-level comparison of host-responses elicited by avian H5N1 and seasonal H1N1 influenza viruses in primary human macrophages.
Specimen part, Subject, Time
View SamplesThe majority of the human genome is transcribed, yielding a rich repository of non-coding transcripts that are involved in a myriad of biological processes including cancer. However, how non-coding transcripts such as Long Non-coding RNAs (lncRNAs) function in prostate cancer is still unclear. In this study, we have identified a novel set of clinically relevant androgen-regulated lncRNAs in prostate cancer. Among this group, we found LINC00844 is a direct androgen regulated target that is actively transcribed in AR-dependent prostate cancer cells. In clinical analysis, the expression of LINC00844 is higher in normal prostate compared to malignant and metastatic prostate cancer samples and patients with low expression demonstrate poor prognosis and significantly increased biochemical recurrence suggesting LINC00844 may function in suppressing tumor progression and metastasis. From in-vitroloss-of-function studies, we showed LINC00844 prevents prostate cancer cell migration and invasion. Moreover, in gene expression studies we demonstrate LINC00844 functions in trans, affecting global androgen-regulated gene transcription. Mechanistically, we provide evidence to show LINC00844 is important in facilitating AR binding to the chromatin. Finally, we showed LINC00844 mediates its phenotypic effects in part by activating the expression of NDRG1, a crucial cancer metastasis suppressor. Collectively, our findings indicate LINC00844 is a novel coregulator of AR that plays an important role in the androgen transcriptional network and the development and progression of prostate cancer.
Novel lncRNA <i>LINC00844</i> Regulates Prostate Cancer Cell Migration and Invasion through AR Signaling.
Cell line, Treatment
View SamplesEpigenetic and genetic regulations are sometimes considered as separate mechanisms that influence gene expression and phenotypes. However, there are DNA sequence variants in epigenetic regulators that could affect gene regulation. The histone demethylase, KDM4C, promotes transcriptional activation by removing the repressive histone mark, tri-methylation of lysine 9 of histone H3 (H3K9me3), from its target genes. In this study, we uncovered cis-acting DNA sequence variants in KDM4C that contribute to individual differences in its expression. Utilizing this natural variation, we performed genetic analyses in B-cells in order to identify target genes that are regulated by KDM4C.
Natural variation in the histone demethylase, KDM4C, influences expression levels of specific genes including those that affect cell growth.
Specimen part
View SamplesInhibition of proteasome degradation pathway has been implicated in neuronal cell death leading to neurodegenerative diseases such as Parkinsons disease and Alzheimers disease. Pharmacological proteasomal inhibitors such as lactacystin can induce apoptosis in cultured mouse cortical neurons through the activation of caspase-3. Furthermore, proteasomal inhibitors are also reported to mediate deleterious alterations in cell cycle regulation, inflammatory processes and protein aggregation and trigger the cell death pathway.
Up-regulation of endoplasmic reticulum stress-related genes during the early phase of treatment of cultured cortical neurons by the proteasomal inhibitor lactacystin.
Specimen part, Time
View SamplesWe carried out a high throughput analysis of insulin-induced kinase signaling pathways in primary fibroblasts from 35 unrelated individuals. We found that extensive individual variation exists in induction of various signaling pathways. ERK signaling displayed the greatest variation, which led to extensive variation in expression of downstream target genes.
Genetic variation in insulin-induced kinase signaling.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
A global transcriptomic view of the multifaceted role of glutathione peroxidase-1 in cerebral ischemic-reperfusion injury.
Treatment
View SamplesIschemic stroke triggers severe focal hypoperfusion accompanied with deprivation of oxygen and glucose to the cerebral tissue, together with loss of ATP, depolorization of neurons, elevated extracellular potassium concentration, and subsequently leads to excitotoxicity as well as increased oxidative stress promoting microvascular injury, blood-brain-barrier deregulation, post-ischemic inflammation and eventually the consequential neurological deficit. Although reperfusion of ischemic brain tissue is critical for restoring normal function, it can paradoxically result in secondary damage, called ischemia/reperfusion (I/R) injury.
A global transcriptomic view of the multifaceted role of glutathione peroxidase-1 in cerebral ischemic-reperfusion injury.
Treatment
View SamplesBody size varies enormously among mammalian species. In small mammals, body growth is typically suppressed rapidly, within weeks, whereas in large mammals, growth is suppressed slowly, over years, allowing for a greater adult size. We recently reported evidence that body growth suppression in rodents is caused in part by a juvenile genetic program that occurs in multiple tissues simultaneously and involves the downregulation of a large set of growth-promoting genes. We hypothesized that this genetic program is conserved in large mammals but that its time course is evolutionarily modulated such that it plays out more slowly, allowing for more prolonged growth. Consistent with this hypothesis, using expression microarray analysis, we identified a set of genes that are downregulated with age in both juvenile sheep kidney and lung. This overlapping gene set was enriched for genes involved in cell proliferation and growth and showed striking similarity to a set of genes downregulated with age in multiple organs of the juvenile mouse and rat, indicating that the multiorgan juvenile genetic program previously described in rodents has been conserved in the 80 million years since sheep and rodents diverged in evolution. Using microarray and real-time PCR, we found that the pace of this program was most rapid in mice, more gradual in rats, and most gradual in sheep. The findings support the hypothesis that a growth-regulating genetic program is conserved among mammalian species but that its pace is modulated to allow more prolonged growth and therefore greater adult body size in larger mammals.
Evolutionary conservation and modulation of a juvenile growth-regulating genetic program.
Specimen part
View SamplesTo examine the differences between bone marrow (BM) and peripheral blood (PB) myeloblasts in acute myeloid leukaemia (AML), we compared CD34+ myeloblasts of paired BM and peripheral blood (PB) samples from AML patients using microarray.
A comparative study of bone marrow and peripheral blood CD34+ myeloblasts in acute myeloid leukaemia.
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